Biaxial testing apparatus are used to control the load placed along varying axes of a test specimen for testing mechanical properties of metals, plastics, composites, wood, fabrics, elastomers and other materials. Examples of biaxial testing equipment may be found in, for example, U.S. Pat. No. 5,905,205 to Clay, U.S. Pat. No. 5,279,166 to Ward et al. and U.S. Pat. No. 7,204,160 to Sadi et al. The present invention relates to a relatively simple and inexpensive fixture that may be simply attached to a universal load frame capable of only uniaxial deformation in order to provide biaxial deformation at different pre-selected ratios. The different ratios are provided by utilizing different gear sets in the testing fixture.